US7834761B2 - H-bridge activator/deactivator and method for activating/deactivating EAS tags - Google Patents
H-bridge activator/deactivator and method for activating/deactivating EAS tags Download PDFInfo
- Publication number
- US7834761B2 US7834761B2 US11/667,991 US66799105A US7834761B2 US 7834761 B2 US7834761 B2 US 7834761B2 US 66799105 A US66799105 A US 66799105A US 7834761 B2 US7834761 B2 US 7834761B2
- Authority
- US
- United States
- Prior art keywords
- junction
- antenna
- current
- cycle
- switch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related, expires
Links
- 230000003213 activating effect Effects 0.000 title claims abstract description 7
- 238000000034 method Methods 0.000 title abstract description 26
- 239000012190 activator Substances 0.000 title description 3
- 230000001965 increasing effect Effects 0.000 claims abstract description 61
- 230000003247 decreasing effect Effects 0.000 claims abstract description 59
- 230000007423 decrease Effects 0.000 claims description 8
- 230000009849 deactivation Effects 0.000 abstract description 43
- 230000007420 reactivation Effects 0.000 abstract description 40
- 230000004913 activation Effects 0.000 abstract description 36
- 239000003990 capacitor Substances 0.000 abstract description 8
- 238000010586 diagram Methods 0.000 description 20
- 238000007599 discharging Methods 0.000 description 19
- 230000006870 function Effects 0.000 description 15
- 101100327917 Caenorhabditis elegans chup-1 gene Proteins 0.000 description 10
- 230000008878 coupling Effects 0.000 description 4
- 238000010168 coupling process Methods 0.000 description 4
- 238000005859 coupling reaction Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000005669 field effect Effects 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 239000003550 marker Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000006842 Henry reaction Methods 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2405—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used
- G08B13/2408—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used using ferromagnetic tags
- G08B13/2411—Tag deactivation
Definitions
- This invention relates to an H-bridge deactivator that utilizes an H-bridge switch network to perform activation, deactivation or reactivation of an electronic article surveillance (EAS) tag and particularly to activation, deactivation or reactivation of an acoustomagnetically activated EAS tag.
- EAS electronic article surveillance
- Acoustomagnetically activated EAS tags are typically demagnetized by a strong magnetic alternating field with a slowly decaying field strength, Conversely, acoustomagnetically activated EAS tags can only be initially activated or subsequently reactivated by magnetizing with a strong constantly positive or constantly negative magnetic field with a slowly decaying field strength.
- AM deactivators require either high voltage (110VAC—volts alternating current) or very high voltage (200-500VDC—volts direct current) in order to generate the high currents required to produce a magnetic field of sufficient magnitude to deactivate an EAS tag.
- the voltages required impose special safety concerns that tend to constrain the design.
- the deactivator will not work for that period of time and such deactivators are not portable.
- the prior solutions address uninterruptible power and portability regarding a small handheld deactivator, but not for a large deactivator or a low voltage deactivator.
- Still another object of the present disclosure is to ensure uninterruptible power for activation, deactivation or reactivation of an EAS tag in case of loss of external power.
- activation, deactivation or reactivation of an EAS tag is accomplished without a high voltage capacitor that is required typically in large deactivation designs, thereby lowering cost and enhancing safety.
- the present disclosure is directed to an apparatus for activating, deactivating or reactivating an electronic article surveillance (EAS) tag by means of an H-bridge circuit coupled to an antenna.
- the H-bridge circuit is adapted to connect to a source of current to the circuit and is configured to direct an increasing current flow through the antenna in a first direction, thereby generating a positive increasing magnetic field from the antenna.
- the H-bridge is configured to direct a decreasing current flow through the antenna in the first direction, thereby generating a positive decreasing magnetic field from the antenna.
- the H-bridge circuit may also be configured to direct an increasing current flow through the antenna in a second direction such that the direction of current flow through the antenna reverses, thereby generating a negative increasing magnetic field from the antenna.
- the H-bridge circuit is configured to direct a decreasing current flow through the antenna in the second direction, thereby generating a negative decreasing magnetic field from the antenna.
- the circuit includes at least four switches and an antenna having first and second ends for directing current through the antenna.
- the first and third switches are coupled to a first junction
- the second and fourth switches are coupled to a second junction.
- the first and fourth switches are coupled to a third junction
- the second and third switches are coupled to a fourth junction.
- the first end of the antenna is coupled to the third junction
- the second end of the antenna is coupled to the fourth junction.
- the first switch controls current between the first junction and the third junction
- the second switch controls current between the second junction and the fourth junction
- the third switch controls current between the first junction and the fourth junction
- the fourth switch controls current between the second junction and the third junction.
- the apparatus may also include a circuit controller controlling the circuit to generate in at least a first cycle a positive increasing magnetic field from the antenna. More particularly, following connection of a source of DC power between the first and second junctions, the circuit controller opens the third and fourth switches, and closes the first switch to direct current from the first junction to the third junction; and closes the second switch to direct current from the fourth junction to the second junction, thereby directing an increasing current through the antenna in a first direction from the third junction to the fourth junction.
- a circuit controller controlling the circuit to generate in at least a first cycle a positive increasing magnetic field from the antenna. More particularly, following connection of a source of DC power between the first and second junctions, the circuit controller opens the third and fourth switches, and closes the first switch to direct current from the first junction to the third junction; and closes the second switch to direct current from the fourth junction to the second junction, thereby directing an increasing current through the antenna in a first direction from the third junction to the fourth junction.
- the circuit controller may also be configured to further control the circuit to generate in the first cycle a positive decreasing magnetic field from the antenna by: disconnecting the source of DC power between the first and second junctions; opening the first, third and fourth switches; and closing the second switch, thereby directing a decreasing current through the antenna in the first direction from the third junction to the fourth junction.
- the circuit controller may be particularly configured to continue to control the circuit to generate in the at least a first cycle a negative increasing magnetic field from the antenna. More particularly, upon connecting a source of DC power between the first and second junctions, the circuit controller opens the first and second switches, and closes the third switch to direct current from the first junction to the fourth junction; and closes the fourth switch to direct current from the third junction to the second junction, thereby directing increasing current through the antenna in a second direction from the fourth junction to the third junction.
- the circuit controller may also be configured to control the circuit to generate in at least the first cycle a negative decreasing magnetic field from the antenna. More particularly, upon disconnecting the source of DC power between the first and second junctions, the circuit controller opens the first, second and third switches; and closes the fourth switch, thereby directing decreasing current through the antenna in the second direction from the fourth junction to the third junction.
- second and succeeding cycles repeat in a similar manner the actions occurring during the first cycle, i.e., generating a positive increasing magnetic field, generating a positive decreasing magnetic field, generating a negative increasing magnetic field and generating a negative decreasing magnetic field. It is contemplated that the cycle time of the first cycle exceeds cycle time of the second cycle, and the cycle time of each succeeding cycle consecutively decreases with respect to the cycle time of the second cycle.
- the antenna is an inductance coil antenna and the switches are high current transistors or field effect transistors.
- the current source may include an AC/DC converter providing DC output, with the AC/DC converter being coupled to a source of AC power.
- the current source may further include a DC/DC High Voltage converter coupled to the AC/DC converter, with the DC/DC High Voltage converter providing DC High Voltage output.
- the current source may include a battery, or may further include an AC/DC charger coupled to the battery to provide DC output, with the AC/DC charger being coupled to a source of AC power.
- the DC output of the AC/DC converter may be either 12 VDC, 24 VDC, or 110 VDC.
- the DC High Voltage output from the DC/DC High Voltage converter may be greater than 110 VDC.
- the voltage output of the battery may be either 12 VDC or 24 VDC.
- the voltage output of the AC/DC charger may be either 12 VDC or 24 VDC.
- the source of AC power may be 110 to 120 VAC.
- the present disclosure is directed to a method of deactivating an electronic article surveillance (EAS) tag which includes the steps of: providing an H-bridge circuit coupled to an antenna; applying a source of current to the H-bridge circuit; directing an increasing current flow through the antenna in a first direction, thereby generating a positive increasing magnetic field from the antenna; directing a decreasing current flow through the antenna in the first direction, thereby generating a positive decreasing magnetic field from the antenna; directing an increasing current flow through the antenna in a second direction such that current flow through the antenna reverses, thereby generating a negative increasing magnetic field from the antenna; and directing a decreasing current flow through the antenna in the second direction, thereby generating a negative decreasing magnetic field from the antenna.
- EAS electronic article surveillance
- the present disclosure is directed to a method of activating or reactivating the electronic article surveillance (EAS) tag which includes the steps of: providing an H-bridge circuit coupled to an antenna; applying a source of current to the H-bridge circuit; directing an increasing current flow through the antenna in a defined direction, thereby generating an increasing magnetic field from the antenna; and directing a decreasing current flow through the antenna in the defined direction, thereby generating a decreasing magnetic field from the antenna.
- the defined direction is a first direction such that the increasing magnetic field is a positive increasing magnetic field and the decreasing magnetic field is a positive decreasing magnetic field.
- the defined direction is (a second direction reverse to the first direction) such that the increasing magnetic field is a negative increasing magnetic field and the decreasing magnetic field is a negative decreasing magnetic field.
- the antenna may include first and second ends for directing current through the antenna and the H-bridge circuit includes at least first, second, third and fourth switches.
- the first and third switches are coupled to a first junction.
- the second and fourth switches coupled to a second junction.
- the first and the fourth switches are coupled to a third junction.
- the second switch and the third switch are coupled to a fourth junction.
- the first end of the antenna is coupled to the third junction and the second end of the antenna is coupled to the fourth junction.
- the first switch controls current between the first junction and the third junction and the second switch controls current between the second junction and the fourth junction.
- the third switch controls current between the first junction and the fourth junction
- the fourth switch controls current between the second junction and the third junction.
- the method may also include implementing the step of directing an increasing current flow through the antenna in a first direction by, in at least a first cycle: connecting the current source between the first and second junctions; opening the third and fourth switches; closing the first switch to direct current from the first junction to the third junction; and closing the second switch to direct current from the fourth junction to the second junction, thereby directing from the third junction to the fourth junction an increasing current through the antenna in the first direction to generate the positive increasing magnetic field.
- the method may also include implementing the step of directing a decreasing current flow through the antenna in a first direction by, in the at least a first cycle: disconnecting the current source between the first and second junctions; opening the first, third and fourth switches; and closing the second switch, thereby directing a decreasing current through the antenna in the first direction from the third junction to the fourth junction to generate the positive decreasing magnetic field.
- the method may also include implementing the step of directing an increasing current flow through the antenna in a second direction such that the current flow through the antenna reverses by, in the at least a first cycle: connecting a current source between the first and second junctions; opening the first and second switches; closing the third switch to direct current from the first junction to the fourth junction; and closing the fourth switch to direct current from the third junction to the second junction, thereby directing from the fourth junction to the third junction increasing current through the antenna in a second direction to generate the negative increasing magnetic field.
- the method may also include implementing the step of directing a decreasing current flow through the antenna in the second direction by, in the at least a first cycle: disconnecting the current source between the first and second junctions; opening the first, second and third switches; and closing the fourth switch, thereby directing decreasing current through the antenna in the second direction from the fourth junction to the third junction to generate the negative decreasing magnetic field.
- the method is implemented typically such that the cycle time of the at least a first cycle exceeds the cycle time of a second cycle, and the cycle time of each succeeding cycle consecutively decreases with respect to the cycle time of the second cycle.
- the antenna is an inductance coil antenna.
- system of the present disclosure includes an EAS label or tag in conjunction with the foregoing features and limitations of the apparatus of the present disclosure.
- H-bridge activation, deactivation or reactivation provides for low voltage (12/24VDC) activation, deactivation or reactivation, uninterruptible power in case of loss of external power, and portability. Furthermore, H-bridge deactivator can perform activation, deactivation or reactivation without a high voltage capacitor, such as is required in most other large deactivation designs.
- FIG. 1 a illustrates a block diagram of an H-bridge acoustomagnetic deactivator that is powered by AC in accordance with one embodiment of the present disclosure
- FIG. 1 b illustrates a block diagram of an H-bridge acoustomagnetic deactivator which is powered by high voltage DC in accordance with an alternate embodiment of the present disclosure
- FIG. 1 c illustrates a block diagram of an H-bridge acoustomagnetic deactivator which is powered by low voltage DC in accordance with an alternate embodiment of the present disclosure
- FIG. 2 a illustrates a circuit diagram of the H-bridge circuit of FIG. 1 a which is powered by AC in accordance with an alternate embodiment of the present disclosure
- FIG. 2 b illustrates a circuit diagram of the H-bridge circuit of FIG. 1 b which is powered by high voltage DC in accordance with an alternate embodiment of the present disclosure
- FIG. 2 c illustrates a circuit diagram of the H-bridge circuit of FIG. 2 c which is powered by DC in accordance with an alternate embodiment of the present disclosure
- FIG. 3 illustrates a graph of the alternating antenna deactivation current as a function of time in accordance with an alternate embodiment of the present disclosure
- FIG. 4 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide positive charging current as a function of time;
- FIG. 5 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide positive discharging current as a function of time;
- FIG. 6 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide negative charging current as a function of time;
- FIG. 7 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide negative discharging current as a function of time;
- FIG. 8 a illustrates a graph of ampere-turns versus the number of turns for #13AWG wire to generate activation, deactivation or reactivation energy for various circuit topologies in accordance with one embodiment of the present disclosure
- FIG. 8 b illustrates a graph of ampere-turns versus the number of turns for #16AWG wire to generate activation, deactivation or reactivation energy for various circuit topologies
- FIG. 8 c illustrates a graph of ampere-turns versus the number of turns for #2AWG wire to generate activation, deactivation or reactivation energy for various circuit topologies
- FIG. 9 illustrates a graph of ON charging time versus current for the H-bridge circuit of FIGS. 2 a , 2 b and 2 c in accordance with one embodiment of the present disclosure.
- FIG. 10 illustrates an enlarged view of the graph of ON charging time versus current for the H-bridge circuit of FIG. 9 in accordance with one embodiment of the present disclosure.
- any reference in the specification to “one embodiment” or “an embodiment” according to the present disclosure means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment.
- the appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
- Coupled and “connected” along with their derivatives. For example, some embodiments may be described using the term “connected” to indicate that two or more elements are in direct physical or electrical contact with each other. In another example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments are not limited in this context.
- FIG. 1 a illustrates a block diagram of an H-bridge acoustomagnetic deactivator 100 a that is powered by AC in accordance with one embodiment of the present disclosure.
- Deactivator 100 a may be configured to include a number of different elements or additional elements may be added to deactivator 100 a , or be substituted for the representative elements shown in FIG. 1 a , and those elements still fall within the scope of the embodiments described herein.
- AC input voltage source 102 provides current and is coupled to AC/DC converter 104 .
- the AC input voltage may range from about 110 to about 120 VAC or from about 220 to about 240 VAC.
- AC/DC converter 104 transmits power to H-bridge 108 via line 106 .
- Antenna 110 receives from the H-bridge 108 alternating and decaying currents “I” required to generate magnetic field “M” for deactivation of EAS tag 130 .
- the constantly positive or constantly negative currents “I” can be applied to activate or reactivate EAS tag 130 .
- a circuit controller section 112 controls activation, deactivation or reactivation timing of the H-bridge circuit 108 .
- the circuit controller section 112 receives feedback from the H-bridge 108 via line 114 and transmits a feedback signal via line 116 to the input of the H-bridge 108 at junction “a” with line 106 .
- FIG. 1 b illustrates a block diagram of an H-bridge acoustomagnetic deactivator 100 b that is powered by high voltage DC in accordance with one embodiment.
- deactivator 100 b may include a number of different elements.
- the H-bridge deactivator circuit 108 and associated components antenna 110 , circuit controller section 112 and EAS tag 130 illustrated in FIG. 1 b are identical to those illustrated in FIG. 1 a , with the exception that DC/DC high voltage converter 120 is connected via line 106 upstream of junction “a” and connected to AC/DC converter 104 via line 122 . Therefore, the DC output voltage of AC/DC converter 104 is increased by a DC/DC high voltage converter 120 (or in other ways known in the art) to supply high voltage DC to H-bridge circuit 108 .
- FIG. 1 c illustrates a block diagram of an H-bridge acoustomagnetic deactivator 100 c that is powered by DC in accordance with one embodiment.
- the H-bridge deactivator circuit 108 and associated components antenna 110 , control section 112 and EAS tag 130 illustrated in FIG. 1 c are identical to those illustrated in FIG. 1 a , with the exception that DC battery 124 is connected via line 106 at junction “b” which is upstream of junction “a” and connected to AC/DC charger 124 .
- Battery 124 is a standard 12V or 24V car, boat, or small plane battery that provides energy storage capability and can be the main power supply input to H-bridge circuit 108 .
- battery 124 has a high cold cranking current capacity in the range of 600 amps and an amp-hour rating in the range of 100 amp-hours.
- FIGS. 2 a to 2 c illustrate an H-bridge circuit 108 which includes four switches SW 1 , SW 2 , SW 3 and SW 4 which are joined at junctions 1 , 2 , 3 and 4 to form a bridge.
- FIG. 2 a illustrates a circuit diagram of the H-bridge circuit 108 of FIG. 1 a that is powered by AC in accordance with one embodiment. Specifically, first switch SW 1 is coupled to first junction 1 and to third junction 3 , second switch SW 2 is coupled to second junction 2 and to fourth junction 4 , third switch SW 3 is coupled to first junction 1 and to fourth junction 4 , and fourth switch SW 4 is coupled to third junction 3 and to second junction 2 .
- First end 110 a of coil antenna 110 is coupled to third junction 3 and second end 110 b of coil antenna 110 is coupled to fourth junction 4 .
- the first switch SW 1 coupled to first junction 1 and to third junction 3
- third switch SW 3 coupled to first junction 1 and to fourth junction 4
- the second switch SW 2 coupled to second junction 2 and fourth junction 4
- fourth switch SW 4 coupled to second junction 2 and third junction 3
- the first switch SW 1 controls current between the first junction 1 and the third junction 3
- the second switch SW 2 controls current between the second junction 2 and the fourth junction 4
- the third switch SW 3 controls current between the first junction 1 and the fourth junction 4 .
- the fourth switch SW 4 controls current between the second junction 2 and the third junction 3 .
- the switches SW 1 , SW 2 , SW 3 and SW 4 include high current transistors which produce currents “I” and, correspondingly, magnetic fields “M” from coil antenna 110 of sufficient magnitude to activate, deactivate or reactivate the EAS tag 130 .
- AC voltage source 102 is coupled in series with rectifier 204 a to junction 1 of the H-bridge circuit 108 through junction “c” and to junction 2 of the H-bridge circuit 108 through junction “d”.
- capacitor 204 b is coupled to the H-bridge circuit 108 through junction 1 and, through junction “d”, coupled to junction 2 of the H-bridge circuit 108 .
- the AC voltage source 102 and rectifier 204 a are also coupled in parallel with capacitor 204 b via junction “a” and junction “d”. Therefore, AC voltage from the AC voltage source 102 is converted via rectifier 204 a and capacitor 204 b to DC and coupled to the H-bridge circuit 108 through junctions 1 , 2 , 3 and 4 .
- FIG. 2 b illustrates a circuit diagram of the H-bridge circuit 108 of FIG. 1 b that is powered by high voltage DC in accordance with one embodiment.
- the H-bridge deactivator circuit 108 and associated rectifier 204 a , capacitor 204 b , SW 1 , SW 2 , SW 3 , SW 4 and antenna 110 are identical to those illustrated in FIG. 2 a , with the exception that DC/DC high voltage converter 120 is connected upstream of junction “a”. Consequently, high voltage DC is supplied to the H-bridge circuit 108 through junctions 1 , 2 , 3 and 4 .
- FIG. 2 c illustrates a circuit diagram of the H-bridge circuit 108 of FIG. 1 c that is powered by DC in accordance with one embodiment.
- the H-bridge deactivator circuit 108 and associated antenna 110 and SW 1 , SW 2 , SW 3 and SW 4 are identical to those illustrated in FIG. 2 a , with the exception that DC battery 124 is connected at junctions “c” and “d” to supply DC power to the H-bridge deactivator 108 through junctions 1 , 2 , 3 and 4 .
- FIG. 3 illustrates a graph of the alternating antenna activation, deactivation or reactivation current as a function of time in accordance with one embodiment.
- the current “I” is plotted as a function of time “t”.
- positive charging currents 301 a , 302 a , 303 a and 304 a are generated.
- the positive charging currents 301 a , 302 a , 303 a and 304 a are followed by positive discharging currents 301 b , 302 b , 303 b and 304 b during which time the current “I” decays to zero.
- an alternating and decaying current “I” can be generated through the coil antenna 110 for deactivation or a constant polarity positive magnetic field or a constant polarity negative magnetic field can be generated for activation or reactivation through the coil antenna 110 .
- the circuit 108 following connection of the source of DC power, such as AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126 , between the first and second junctions 1 and 2 , respectively, to apply current to the circuit 108 , the circuit 108 generates in a first cycle C 1 a positive increasing magnetic field from the antenna 110 by virtue of the circuit controller 112 opening the third switch SW 3 ; opening the fourth switch SW 4 ; closing the first switch SW 1 to direct current “I” from the first junction 1 to the third junction 3 ; and closing the second switch SW 2 to direct current “I” from the fourth junction 4 to the second junction 2 , thereby directing an increasing current 301 a through the antenna 110 in a first direction from the third junction 3 to the fourth junction 4 .
- the source of DC power such as AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126
- the circuit controller 112 further generates in the first cycle C 1 a positive decreasing magnetic field from the antenna 110 by disconnecting the source of DC power, (e.g., AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126 ) between the first and second junctions 1 and 2 , respectively; opening the first switch SW 1 ; opening the third switch SW 3 ; opening the fourth switch SW 4 ; and closing the second switch SW 2 , thereby directing a decreasing current 301 b through the antenna 110 in a first direction from the third junction 3 to the fourth junction 4 .
- the source of DC power e.g., AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126
- the circuit controller 112 continues to generate in the first cycle C 1 a negative increasing magnetic field from the antenna 110 by connecting a source of DC power (e.g., AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126 ) between the first and second junctions, 1 and 2 , respectively; opening the first switch SW 1 ; opening the second switch SW 2 ; closing the third switch SW 3 to direct the current “I” from the first junction 1 to the fourth junction 4 ; and closing the fourth switch SW 4 to reverse current flow through the antenna 10 by directing the current “I” from the third junction 1 to the second junction 2 , thereby directing increasing current 301 c through the antenna 110 in a second direction from the fourth junction 4 to the third junction 3 which is a direction reverse to the first direction.
- a source of DC power e.g., AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126
- the circuit controller 112 is also configured to generate a negative decreasing magnetic field from the antenna 110 by disconnecting the source of DC power (i.e., an AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126 ) between the first and second junctions, 1 and 2 , respectively; opening the first switch SW 1 ; opening the second switch SW 2 ; opening the third switch SW 3 ; and closing the fourth switch SW 4 , thereby directing decreasing current 301 d through the antenna 110 in a second direction from the fourth junction 4 to the third junction 3 .
- DC power i.e., an AC/DC converter 104 , DC/DC High Voltage converter 120 , battery 124 or AC/DC charger 126
- the circuit In a second cycle C 2 and succeeding cycles such as C 3 and C 4 , following connection of the source of DC power between the first and second junctions, the circuit generates from the antenna 110 in the second and succeeding cycles C 2 through C 4 initially a positive increasing magnetic field, followed by positive decreasing magnetic field, a negative increasing magnetic field, and a negative decreasing magnetic field, by virtue of the circuit controller 112 repeating the same steps as disclosed above for the first cycle C 1 .
- cycle time of the first cycle C 1 exceeds cycle time of the second cycle C 2
- cycle time of each succeeding cycle such as cycles C 3 and C 4 , consecutively decreases with respect to the cycle time of the second cycle C 2 .
- the alternating current “I” can be designed to activate, deactivate or reactivate an AM label.
- the alternating current “I” can be designed to activate, deactivate or reactivate an AM label.
- four positive charging Switch “ON” times T 1 , T 2 , T 3 and T 4 and four cycles C 1 through C 4 are illustrated in FIG. 3 , those skilled in the art recognize that any number of Switch “ON” times, either greater than or less than four, and any number of cycles can be generated as required or preferred to activate, deactivate or reactivate a particular acoustomagnetic (AM) label.
- AM acoustomagnetic
- Equation (1) is the equation for charging the circuit.
- I ⁇ V/R ⁇ e ⁇ t/(L/R) (2)
- V Battery voltage (12 or 24VDC)
- R Antenna resistance in ohms ( ⁇ )
- e Natural number 2.71828
- the battery 124 is typically a standard car, boat or small plane battery with high cold cranking amps ( ⁇ 600) and a high amp-hour rating ( ⁇ 100).
- the antenna 110 is made from large gauge cable to minimize losses, wrapped “N” times in a loop of arbitrary shape, usually circular or square. This multiple looping around an area creates an inductance “L” and a resistance “R”. The losses are proportional to the resistance “R”. The rate of rise of the charge current “I” and the rate of discharge of that current “I” is proportional to the ratio of L/R.
- the ratio L/R is known as the time constant “ ⁇ ”.
- N number of turns or wraps of the antenna cable.
- FIG. 4 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide positive charging current “I” as a function of time “t” in accordance with one embodiment.
- the positive charging currents 301 a , 302 a , 303 a and 304 a of FIG. 3 are generated through coil antenna 110 as illustrated in FIG. 4 by closing SW 1 and SW 2 , with SW 3 and SW 4 being open, for the charge time T 1 , T 2 , T 3 and T 4 .
- Equation (1) provides the calculation for the charging current “I”.
- FIG. 5 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide positive discharging current “I” as a function of time “t” in accordance with one embodiment.
- the positive discharging currents 301 b , 302 b , 303 b and 304 b of FIG. 3 are generated through coil antenna 110 as illustrated in FIG. 5 by closing SW 2 , with SW 1 , SW 3 , and SW 4 being open, for the discharge time.
- Equation (2) provides the calculation for the discharging current “I”.
- FIG. 6 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide negative charging current “I” as a function of time “t” in accordance with one embodiment.
- the negative charging currents 301 c , 302 c , 303 c and 304 c of FIG. 3 are generated through coil antenna 110 as illustrated in FIG. 6 by closing SW 3 and SW 4 , with SW 1 and SW 2 being open for the charge time.
- the negative charging currents are generated by increasing current through the coil antenna 110 with the currents 301 c , 302 c , 303 c and 304 c being in the direction opposite to that of the positive charging currents 301 a , 302 a , 303 a and 304 a illustrated in FIG. 4 .
- Equation (1) provides the calculation for the charging current “I”.
- FIG. 7 illustrates an equivalent circuit diagram of the H-bridge circuit of FIGS. 2 a , 2 b and 2 c illustrating the equivalent circuit configuration to provide negative discharging current “I” as a function of time in accordance with one embodiment.
- the negative discharging currents 301 d , 302 d , 303 d and 304 d of FIG. 3 are generated through coil antenna 110 as illustrated in FIG. 7 by closing SW 4 , with SW 1 , SW 2 , and SW 3 being open for the discharge time.
- Equation (2) provides the calculation for the discharging current “I”.
- Decaying amplitude pulses i.e. discharging currents, are calculated by solving Equations (1) and (2) for time “t” at a desired current “I”.
- the Amp-Turns product is a measure of the magnetic field strength of the activator, deactivator or reactivator
- the activation, deactivation or reactivation energy is a function of the number of turns required to generate the magnetic field strength required to deactivate an EAS tag.
- AT is the product of the number of turns (N) times the peak current (I).
- An AT product of 10000-15000 is comparable to existing deactivators of similar size.
- An acoustomagnetic EAS tag such as EAS tag 130 can be activated or reactivated by coupling to just the positive charging magnetic fields 301 a , 302 a , 303 a , 304 a and to the positive discharging magnetic fields 301 b , 302 b , 303 b , 304 b or by coupling to just the negative charging magnetic fields 301 c , 302 c , 303 c , 304 c and to the negative discharging magnetic fields 301 d , 302 d , 303 d , 304 d , but not to an alternating magnetic field which varies from positive to negative or from negative to positive.
- the H-bridge circuit 108 is not only a deactivator circuit but also an activator or a reactivator circuit.
- a method of activating or reactivating the electronic article surveillance (EAS) tag 130 includes the steps of: providing the H-bridge circuit 108 coupled to the antenna 110 ; applying a source of current I to the H-bridge circuit 108 ; directing an increasing current flow I through the antenna 110 in a defined direction, thereby generating an increasing magnetic field M from the antenna 110 ; and directing a decreasing current flow I through the antenna 110 in the defined direction, thereby generating a decreasing magnetic field M from the antenna 110 .
- the defined direction is a first direction such that the increasing magnetic field M is a positive increasing magnetic field and the decreasing magnetic field M is a positive decreasing magnetic field M.
- the defined direction is a second direction reverse to the first direction such that the increasing magnetic field M is a negative increasing magnetic field and the decreasing magnetic field M is a negative decreasing magnetic field M.
- coupling of EAS tag 130 to just the positive charging magnetic fields 301 a , 302 a , 303 a , 304 a and to the positive discharging magnetic fields 301 b , 302 b , 303 b , 304 b can be effected, as previously discussed, by operating only switches SW 1 and SW 2 .
- Switches SW 1 , SW 2 , SW 3 and SW 4 each include a bypass diode d 1 , d 2 , d 3 and d 4 , respectively, which bypasses the switch to allow current decay in the normal direction of current flow through the respective switch upon closure of the switch while disallowing current flow in the reverse direction.
- coupling of EAS tag 130 to just the negative charging magnetic fields 301 c , 302 c , 303 c , 304 c and to the negative discharging magnetic fields 301 d , 302 d , 303 d , 304 d can be effected, as previously discussed, by operating only switches SW 3 and SW 4 .
- FIGS. 8 a - c shows the number of turns required to generate activation, deactivation or reactivation energy for various circuit topologies.
- FIG. 8 a illustrates a graph of ampere-turns AT or NI(N) versus the number of turns N for #13AWG wire to generate activation, deactivation or reactivation energy for various circuit topologies in accordance with one embodiment.
- FIG. 8 b illustrates a graph of ampere-turns AT or NI(N) versus the number of turns N for #16AWG wire to generate activation, deactivation or reactivation energy for various circuit topologies in accordance with one embodiment.
- FIG. 8 c illustrates a graph of ampere-turns AT or NI(N) versus the number of turns N for #2AWG wire to generate activation, deactivation or reactivation energy for various circuit topologies in accordance with one embodiment.
- the resistivity of the wire is 156 ⁇ 10 ⁇ 6 ⁇ /ft.
- the wire gauge can vary as smaller diameter wire can be used in higher voltage topologies.
- the activation, deactivation or reactivation frequency increases as the current activation, deactivation or reactivation waveform decays because, as can be seen from FIG. 3 , the interval between Switch “ON” times T 1 , T 2 , T 3 and T 4 decreases. That is, the positive and negative charging currents “I” are shut off earlier and earlier, corresponding to an increase in the deactivation frequency.
- the “ON” time of the switches SW 1 , SW 2 , SW 3 and SW 4 which are comprised of FETs, is calculated by solving Equations 1 and 2 for time “t”.
- FIG. 9 illustrates a graph of “ON” charging time “t” versus current “I” for the H-bridge circuit of FIGS. 2 a , 2 b and 2 c in accordance with one embodiment.
- FIG. 10 illustrates an enlarged view of the graph of “ON” charging time versus current for the H-bridge circuit of FIG. 9 in accordance with one embodiment.
- a method for activating or deactivating or reactivating an EAS tag 130 which includes the steps of: providing an H-bridge circuit 108 coupled to an antenna 110 ; applying a source of current via line 106 to the H-bridge circuit 108 ; and directing an increasing current flow I through the antenna 110 in a first direction, thereby generating a positive increasing magnetic field M from the antenna, or directing a decreasing current flow I through the antenna 110 in the first direction, thereby generating a positive decreasing magnetic field M from the antenna 110 ; directing an increasing current flow I through the antenna 110 in a second direction such that direction of current flow I through the antenna 110 is in a direction reverse to that of direction of current flow I in the first direction, thereby generating a negative increasing magnetic field M from the antenna 110 , or directing a decreasing current flow I through the antenna 110 in the
- the method may be implemented such that the antenna 110 includes first and second ends for directing current I through the antenna 110 and the H-bridge circuit 108 includes first, second, third and fourth switches SW 1 , SW 2 , SW 3 and SW 4 , respectively.
- the first and third switches SW 1 and SW 3 may be coupled to a first junction 1 ; the second and fourth switches SW 2 and SW 4 may be coupled to a second junction 2 ; the first and the fourth switches SW 1 and SW 4 may be coupled to a third junction 3 ; and the third switch SW 3 and the second switch SW 2 may be coupled to a fourth junction 4 .
- the first end 110 a of the antenna 110 may be coupled to the third junction 3 and the second end 110 b of the antenna 110 may be coupled to the fourth junction 4 .
- the first switch SW 1 may control current I between the first junction 1 and the third junction 3 ;
- the second switch SW 2 may control current I between the second junction 2 and the fourth junction 4 ;
- the third switch SW 3 may control current I between the first junction 1 and the fourth junction 4 ;
- the fourth switch SW 4 may control current I between the second junction 2 and the third junction 3 .
- the method may further be implemented such that the step of directing an increasing current flow I through the antenna 110 in a first direction is performed by: connecting the current source via line 106 between the first and second junctions, 1 and 2 ; opening the third and fourth switches, SW 3 and SW 4 , closing the first switch SW 1 to direct current I from the first junction 1 to the third junction 3 ; and closing the second switch SW 2 to direct current I from the fourth junction 4 to the second junction 2 , thereby directing from the third junction 3 to the fourth junction 4 an increasing current I through the antenna 110 in the first direction to generate the positive increasing magnetic field M.
- the method may further be implemented such that the step of directing a decreasing current flow I through the antenna 110 in a first direction is performed by: disconnecting the current source via line 106 between the first and second junctions 1 and 2 ; opening the first, third and fourth switches SW 1 , SW 3 and SW 4 ; and closing the second switch SW 2 , thereby directing a decreasing current I through the antenna 110 in the first direction from the third junction 3 to the fourth junction 4 to generate the positive decreasing magnetic field M.
- the method may further be implemented such that the step of directing an increasing current flow I through the antenna 110 in a second direction is performed by: connecting the current source via line 106 between the first and second junctions 1 and 2 ; opening the first and second switches SW 1 and SW 2 ; closing the third switch SW 3 to direct current I from the first junction 1 to the fourth junction 4 ; and closing the fourth switch SW 4 to direct current I from the third junction 3 to the second junction 2 , thereby directing from the fourth 4 junction to the third junction 3 increasing current I through the antenna 110 in a second direction to generate the negative increasing magnetic field M.
- the method may further be implemented such that the step of directing a decreasing current flow through the antenna in the second direction is performed by: disconnecting the current source between the first and second junctions; opening the first, second and third switches; and closing the fourth switch, thereby directing decreasing current through the antenna in the second direction from the fourth junction to the third junction to generate the negative decreasing magnetic field.
- the present disclosure provides an alternate method for activation, deactivation or reactivation of an EAS acoustomagnetically activated tag by utilizing an H-bridge circuit to generate the alternating and decaying currents required for activation, deactivation or reactivation.
- the present disclosure enables low voltage activation, deactivation or reactivation of an EAS tag, e.g., at voltage levels of 12 to 24VDC, and ensures uninterruptible power for activation, deactivation or reactivation of an EAS tag in case of external power loss.
- the present disclosure provides a portable apparatus for activation, deactivation or reactivation of an EAS tag and the activation, deactivation or reactivation can be performed without a high voltage capacitor that is required typically in large deactivation designs.
- the present disclosure provides alternate methods of activation, deactivation or reactivation so that a designer may optimize for a particular environment.
- Some embodiments may be implemented using an architecture that may vary in accordance with any number of factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds and other performance constraints.
- an embodiment may be implemented using software executed by a general-purpose or special-purpose processor.
- an embodiment may be implemented as dedicated hardware, such as a circuit, an application specific integrated circuit (ASIC), programmable logic device (PLD) or digital signal processor (DSP), and so forth.
- ASIC application specific integrated circuit
- PLD programmable logic device
- DSP digital signal processor
- an embodiment may be implemented by any combination of programmed general-purpose computer components and custom hardware components. The embodiments are not limited in this context.
Abstract
Description
I={V/R}[1−e {−t/(L/R)}] (1)
Equation (1) is the equation for charging the circuit.
I={V/R}e −t/(L/R) (2)
Equation (2) is the equation for discharging the circuit, where for both Equations (1) and (2):
I=Current in amps (A)
V=Battery voltage (12 or 24VDC)
R=Antenna resistance in ohms (Ω)
e=Natural number 2.71828
L=Antenna inductance in henrys (H)
t=time in seconds (s)
R=ρlen (3)
where len=length of the cable, and the length of the cable, len, is given by Equation (4), as follows:
len=NC (4)
C=πD (5)
R=ρNπ/D (6)
L=μN 2 A/len (7)
where
μ=permeability of free space, i.e.,
μ=4×10−7 H/m
N=number of turns in the antenna, and
A=area of loop in the antenna.
A=πD 2/4 (8)
R(N)=ρNπ+0.01 (9)
where 0.01 is the resistance in ohms (Ω) of two power field effect transistors (FETs) and ρ is the electrical resistivity of the metal conductor cable in ohm/ft. FETs when in the ON position are high current transistors and when in the OFF position are high impedance transistors.
ACTION STATE | SW1 | SW2 | SW3 | SW4 | |||||
Positive Charging | ON | | OFF | OFF | |||||
301a, 302a, 303a, 304a | |||||||||
Positive Discharging | OFF | ON | | OFF | |||||
301b, 302b, 303b, 304b | |||||||||
Negative Charging | OFF | | ON | ON | |||||
301c, 302c, 303c, 304c | |||||||||
Negative Discharging | OFF | | OFF | ON | |||||
301d, 302d, 303d, 304d | |||||||||
I(N)=V/R(N) (10)
where V=110VDC for AC/DC applications, or V>110VDC for DC/DC high voltage application or V=12VDC or 24VDC for battery application.
NI(N)=N·I(N) (11)
t(I)=−τ{1−(IR)/V} (12)
t(I)=−τ{(IR)/V} (13)
Claims (20)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/667,991 US7834761B2 (en) | 2004-11-22 | 2005-11-18 | H-bridge activator/deactivator and method for activating/deactivating EAS tags |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US62995604P | 2004-11-22 | 2004-11-22 | |
PCT/US2005/041678 WO2006057887A1 (en) | 2004-11-22 | 2005-11-18 | H-bridge activator/deactivator and method for activating/deactivating eas tags |
US11/667,991 US7834761B2 (en) | 2004-11-22 | 2005-11-18 | H-bridge activator/deactivator and method for activating/deactivating EAS tags |
Publications (2)
Publication Number | Publication Date |
---|---|
US20090121871A1 US20090121871A1 (en) | 2009-05-14 |
US7834761B2 true US7834761B2 (en) | 2010-11-16 |
Family
ID=36087832
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/667,991 Expired - Fee Related US7834761B2 (en) | 2004-11-22 | 2005-11-18 | H-bridge activator/deactivator and method for activating/deactivating EAS tags |
Country Status (7)
Country | Link |
---|---|
US (1) | US7834761B2 (en) |
EP (1) | EP1815449A1 (en) |
JP (1) | JP2008521351A (en) |
CN (1) | CN101088110A (en) |
AU (1) | AU2005309792A1 (en) |
CA (1) | CA2587871A1 (en) |
WO (1) | WO2006057887A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100141304A1 (en) * | 2007-07-03 | 2010-06-10 | Mitsubishi Electric Corporation | Drive circuit for power element |
US8381979B2 (en) | 2011-01-31 | 2013-02-26 | Metrologic Instruments, Inc. | Bar code symbol reading system employing EAS-enabling faceplate bezel |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010148038A1 (en) * | 2009-06-15 | 2010-12-23 | Adel Odeh Sayegh | Article surveillance system |
CA2909650C (en) * | 2013-03-14 | 2022-05-03 | Ronald B. Easter | Mobile eas deactivator |
US10332725B2 (en) * | 2015-03-30 | 2019-06-25 | Lam Research Corporation | Systems and methods for reversing RF current polarity at one output of a multiple output RF matching network |
CN106997644A (en) * | 2016-01-22 | 2017-08-01 | 罗存 | Automatic counting decoder based on 58KHZ sound magnetic |
KR102494550B1 (en) * | 2016-10-12 | 2023-02-02 | 주식회사 위츠 | Apparatus for transmiting power wirelessly |
WO2019194793A1 (en) * | 2018-04-03 | 2019-10-10 | Tyco Fire & Security Gmbh | Systems and methods for deactivation frequency reduction using a transformer |
WO2023079878A1 (en) * | 2021-11-05 | 2023-05-11 | ローム株式会社 | Driver device, water treatment device, and motor drive device |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4524773A (en) * | 1983-08-24 | 1985-06-25 | The John Hopkins University | Apparatus for inhibiting self-injurious behavior (SIB) in patients |
US5210524A (en) * | 1990-05-16 | 1993-05-11 | Minnesota Mining And Manufacturing Company | Electro-magnetic desensitizer |
US5805065A (en) * | 1991-05-08 | 1998-09-08 | Minnesota Mining And Manufacturing Company | Electro-magnetic desensitizer |
US20080088460A1 (en) * | 2004-11-15 | 2008-04-17 | Sensormatic Electronics Corporation | Combination eas and rfid label or tag using a hybrid rfid antenna |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5493275A (en) * | 1994-08-09 | 1996-02-20 | Sensormatic Electronics Corporation | Apparatus for deactivation of electronic article surveillance tags |
US5917412A (en) * | 1997-05-21 | 1999-06-29 | Sensormatic Electronics Corporation | Deactivation device with biplanar deactivation |
US5907465A (en) * | 1998-08-13 | 1999-05-25 | Sensormatic Electronics Corporation | Circuit for energizing EAS marker deactivation device with DC pulses of alternating polarity |
US6700489B1 (en) * | 2000-11-27 | 2004-03-02 | Sensormatic Electronics Corporation | Handheld cordless deactivator for electronic article surveillance tags |
US6696951B2 (en) * | 2001-06-13 | 2004-02-24 | 3M Innovative Properties Company | Field creation in a magnetic electronic article surveillance system |
US6822570B2 (en) * | 2001-12-20 | 2004-11-23 | Calypso Medical Technologies, Inc. | System for spatially adjustable excitation of leadless miniature marker |
-
2005
- 2005-11-18 JP JP2007543234A patent/JP2008521351A/en not_active Withdrawn
- 2005-11-18 WO PCT/US2005/041678 patent/WO2006057887A1/en active Application Filing
- 2005-11-18 CA CA002587871A patent/CA2587871A1/en not_active Abandoned
- 2005-11-18 US US11/667,991 patent/US7834761B2/en not_active Expired - Fee Related
- 2005-11-18 EP EP05826074A patent/EP1815449A1/en not_active Ceased
- 2005-11-18 CN CNA2005800447955A patent/CN101088110A/en active Pending
- 2005-11-18 AU AU2005309792A patent/AU2005309792A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4524773A (en) * | 1983-08-24 | 1985-06-25 | The John Hopkins University | Apparatus for inhibiting self-injurious behavior (SIB) in patients |
US5210524A (en) * | 1990-05-16 | 1993-05-11 | Minnesota Mining And Manufacturing Company | Electro-magnetic desensitizer |
US5805065A (en) * | 1991-05-08 | 1998-09-08 | Minnesota Mining And Manufacturing Company | Electro-magnetic desensitizer |
US20080088460A1 (en) * | 2004-11-15 | 2008-04-17 | Sensormatic Electronics Corporation | Combination eas and rfid label or tag using a hybrid rfid antenna |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100141304A1 (en) * | 2007-07-03 | 2010-06-10 | Mitsubishi Electric Corporation | Drive circuit for power element |
US8040162B2 (en) * | 2007-07-03 | 2011-10-18 | Mitsubishi Electric Corporation | Switch matrix drive circuit for a power element |
US8381979B2 (en) | 2011-01-31 | 2013-02-26 | Metrologic Instruments, Inc. | Bar code symbol reading system employing EAS-enabling faceplate bezel |
US9081995B2 (en) | 2011-01-31 | 2015-07-14 | Metrologice Instruments, Inc. | Bar code symbol reading system employing EAS-enabling faceplate bezel |
Also Published As
Publication number | Publication date |
---|---|
US20090121871A1 (en) | 2009-05-14 |
CA2587871A1 (en) | 2006-06-01 |
EP1815449A1 (en) | 2007-08-08 |
CN101088110A (en) | 2007-12-12 |
AU2005309792A1 (en) | 2006-06-01 |
JP2008521351A (en) | 2008-06-19 |
WO2006057887A1 (en) | 2006-06-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7834761B2 (en) | H-bridge activator/deactivator and method for activating/deactivating EAS tags | |
CA2567031C (en) | Deactivator using resonant recharge | |
JP4620809B2 (en) | Deactivation device that performs 2-side deactivation | |
US8970223B2 (en) | Apparatus for VLF-voltage testing of cables | |
US5852555A (en) | Dual inverter power supply | |
US4742208A (en) | Welding system with electronic control | |
AU2005274009B2 (en) | Deactivator using inductive charging | |
AU2006255614A1 (en) | Techniques for deactivating electronic article surveillance labels using energy recovery | |
JPS6122560B2 (en) | ||
US20170272003A1 (en) | Power Supplies Having Synchronous And Asynchronous Modes Of Operation | |
US7109437B2 (en) | Electric ARC welder with background current | |
EP1524636B1 (en) | Electronic article surveillance marker deactivator using phase control deactivation | |
JPH09308134A (en) | Uninterruptible power supply unit | |
JP3806479B2 (en) | Current transformer | |
JP2858008B2 (en) | Battery charger | |
EP4350719A1 (en) | Direct-current magnetic field superconducting coil power supply device | |
Sreeram | Universal matrix converter for AC and DC power conversions | |
JPH11285253A (en) | Power supply | |
JPH06160438A (en) | Method for detecting output current of inverter | |
JP2001025240A (en) | Dc power source circuit | |
Pitel | Demagnetizing inverter using memory state switching techniques | |
Lee et al. | An Implementation of a Current Controlled Bi-directional Inverter with ZVT Switching | |
JPS6059834B2 (en) | pulse power supply | |
JPS58111304A (en) | Superconducting electromagnet device | |
JP2000299633A (en) | Open/close device for ac power source circuit |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SENSORMATIC ELECTRONICS CORPORATION, FLORIDA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LEONE, STEVEN V.;REEL/FRAME:019358/0736 Effective date: 20041119 |
|
AS | Assignment |
Owner name: SENSORMATIC ELECTRONICS CORPORATION, FLORIDA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LEONE, STEVEN V.;REEL/FRAME:021503/0862 Effective date: 20080830 |
|
AS | Assignment |
Owner name: SENSORMATIC ELECTRONICS, LLC,FLORIDA Free format text: MERGER;ASSIGNOR:SENSORMATIC ELECTRONICS CORPORATION;REEL/FRAME:024213/0049 Effective date: 20090922 Owner name: SENSORMATIC ELECTRONICS, LLC, FLORIDA Free format text: MERGER;ASSIGNOR:SENSORMATIC ELECTRONICS CORPORATION;REEL/FRAME:024213/0049 Effective date: 20090922 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
AS | Assignment |
Owner name: ADT SERVICES GMBH, SWITZERLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SENSORMATIC ELECTRONICS, LLC;REEL/FRAME:029894/0856 Effective date: 20130214 |
|
AS | Assignment |
Owner name: TYCO FIRE & SECURITY GMBH, SWITZERLAND Free format text: MERGER;ASSIGNOR:ADT SERVICES GMBH;REEL/FRAME:030290/0731 Effective date: 20130326 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552) Year of fee payment: 8 |
|
AS | Assignment |
Owner name: SENSORMATIC ELECTRONICS, LLC, FLORIDA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TYCO FIRE & SECURITY GMBH;REEL/FRAME:047182/0674 Effective date: 20180927 |
|
AS | Assignment |
Owner name: SENSORMATIC ELECTRONICS, LLC, FLORIDA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TYCO FIRE & SECURITY GMBH;REEL/FRAME:047188/0715 Effective date: 20180927 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20221116 |